vlib/v/checker/tests/unsafe_fixed_array_assign.vv:10:10: notice: left-side of assignment expects a mutable reference, but variable `a` is immutable, declare it with `mut` to make it mutable or clone it
    8 | }
    9 | a := [&box]!
   10 | mut b := a
      |          ^
   11 | b[0].num = 0
   12 | println(a)
vlib/v/checker/tests/unsafe_fixed_array_assign.vv:10:7: error: assignment from one fixed array to another with a pointer element type is prohibited outside of `unsafe`
    8 | }
    9 | a := [&box]!
   10 | mut b := a
      |       ~~
   11 | b[0].num = 0
   12 | println(a)
